The selection-multi file lets you bundle property/value pairs into a single group using attrs instead of calling a single attr for every propery/value pair. It's also nice that you won't have to use quotes for the key (property) name when you bundle them into an object. Same goes for style vs styles and property vs properties.

Navigate to your project folder:

cd path/to/project-folder

Start a Python web server:

python -m SimpleHTTPServer 8888 &

Make sure to start the server in the folder with the files you want served.

If the port number is already in use, kill the process or use a different port number.

To kill a process, first find the id of the process (PID) using the port: